Heart failure is a chronic, progressive condition in which heart muscle is unable to pump sufficient blood to meet the body's needs. A healthy heart pumps blood continuously through the circulatory system to deliver oxygen- and nutrient-rich blood to the body's cells and permit normal functioning. A variety of diseases and conditions, however, can weaken the heart and reduce its ability to deliver an adequate blood supply, such as hypertension, coronary artery disease and others. It is estimated that more than 20 million individuals worldwide, including five to six million in the United States (U.S.), suffer from heart failure. It is the most common diagnosis for hospital admission in the U.S. for patients over the age of 65.
Most existing therapies target indirect methods that reduce the workload on the heart, but do not directly improve heart function. For example, ACE inhibitors widen blood vessels (vasodilation) to lower blood pressure and reduce the resistance against which the heart must pump. These therapies, however, do not directly improve the heart's ability to contract normally. Existing therapies also provide only short-term symptomatic relief, and therefore require multiple repeat infusions at a high frequency. Hence, there is a need for alternative treatments for heart failure.